Because this week sees the release of "Feedback," the new album from Jurassic 5, and the album features the single "Don't Stop." And "Don't Stop" features, you guessed it, Dave Matthews Band.

And it rocks (listen here for proof). Jurassic 5 has long been one of my favorite hip-hop acts. Their best material has a laid back flow that's perfect for chilling in the current heat wave. The guys always seem like they're having a good time, mostly becasue their lyrics are so witty. It helps, too, that they generally rhyme about positivity, political consciousness, and resisting the assault of consumer culture. Listen to enough of their tracks, and you feel like you can go out and change a few things, dammit, without ever breaking a sweat.

The group's cool gets bolstered by their sound. Their musical pallette is dense with instruments--none of the single-note-repeating that makes much commercial hip-hop sound unimaginative. Jurassic 5 might throw in in a steel guitar, a xylophone, or an old blues riff. You just don't know.

And their tempos are of the super-fly, pimp-walk variety. You know, mellow and funky and guaranteed to cause a strut.

And given that vibe, I'm surprised to see them collaborating with a frat-rocker like Dave Matthews. But there he is, singing harmony with himself on "Don't Stop." The song sounds like "Where Is The Love"--the Black-Eyed Peas' collaboration with Justin Timberlake--but with more street cred. There's a gentle insistence to the beat, a sung chorus about people getting along, and the clever J-5 verses we all can love.

Played at medium volume, the song is a perfect chill-out track. Listen especially for the weird echo the producers put on Dave's vocals. It makes him sound like the aural equivalent of a lava lamp, sliding and stretching.

In short, "Don't Stop" makes Dave Matthews sound cool. Something I never thought I would say. I mean, that's about as likely as John Mayer sounding genuine.

Rrrgh. Even the mention of John Mayer makes me angry. For the most part, I find his music to be the worst kind of cynical marketing ploy. It's like Mayer thought, "Hey! Ladies of all ages love non-threatening male singers! Why don't I record some breathy-voiced, sentimental songs about blandly universal topics like hating high school and wishing that fathers could be good to their daughters? Then all the daughters will want to sleep with me. And that'll be the undercurrent of my hit song 'Daughters,' but no one will notice it as they're turning my faux-sensitive lyrics into ads for perfume!"

Okay, maybe he didn't think all those things at one time, but I sure do. Mayer sounds like the more calculated version of Josh Rouse, keeping the Americana influences but dispensing with the wry lyrics. He postures like James Taylor, but lacks the dark back story. He is so inoffensive--naming his first album "Room for Squares" even--that he turns the corner right back to offensiveness, especially because in interviews he seems so proud of himself for being a swell guy that your sister could date.

I've always loved that Mayer named his second album "Heavier Things" and proceeded to churn out the same old easy listening tripe. Adding electric guitars just made him louder, not heavier. His voice remained thin and unupported. His lyrics stayed about as deep as 8th grade poetry. ("Someday I'll fly/ Someday I'll soar/ Someday I'll be so damn much more/ 'Cause I'm bigger than my body gives me credit for). I was ready to go on hating him forever, even naming "Daughters" my least favorite single of 2004.

Yesterday, though, I had to eat a little crow. I heard Mayer's new single "Waiting on the World to Change," and I had to admit that, this time at least, he had actually captured the 70s rock groove instead of just aping it. (Judge for yourself.)

What is it about this song that makes it sound honest to me? For one, Mayer's voice actually has some muscle in it. He digs down to the deeper end of his range to growls out a few words of disgust for the current political climate. Oh, right, and he also sings about politics, which makes this song akin to folkie protest tunes of my parents' time.

And for once, Mayer sings over an instrumental track with attitude. There's a lazy drum beat and nice bass line that make "Waiting" sound like a back porch jam. It's pleasant and accessible, but it isn't overproduced. It sounds relaxed and fun, like it got recorded in 1972 while some kids were running through a sprinkler

Who'd have thought?

Next thing you know, I'll hear some song from Insane Clown Posse and decide I wrote them off too soon.